How can I change individual items in my agenda so that although they may
have a date of 2017-09-01 and be repeated daily but haven't been
accessed in the intervening time period, I can easily change it to miss
out all the unexpired dates and be rescheduled for a date of my choosing
please?

I seem to remember that there was some way, either through a add-on
package or a sequence of commands, but I can't seem to find it now.

Thanks
Sharon.
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